Project Summary Sexual Compulsivity (SC), or high levels of sexual behavior combined with a perceived lack of control, is strongly associated with unprotected sex and other HIV sexual risk behaviors. This association has been ro- bust across populations, but particularly strong in men who have sex with men (MSM). This proposal builds on our previous research which found that SC is associated with sero-discordant unprotected anal intercourse in HIV-positive MSM even after controlling for other known correlates (e.g., condom use self-efficacy, intentions to practice safer sex, etc.). However, while the association between SC and unsafe sex has considerable em- pirical support, the manner in which SC confers this increased risk, and therefore how to best influence such processes in order to reduce risk, is as yet, unknown. SC has been conceptualized as an addictive disorder, an impulsive disorder, and as a compulsive disorder. Others have questioned the existence of SC as a defin-able disorder and attribute the increased sexual behavior to high sex drive. Common across all conceptualiza-tions are four factors: negative affect, sexual arousal, behavioral inhibition, and cognitive control. These fac- tors influence HIV risk by interfering with the ability to manage one's sexual impulses, which would lead to multiple sexual encounters, and through impairments in the ability to consider multiple reinforcement contin- gencies and to consider the long-term consequences of pleasurable behavior which interferes with condom use. This study will provide needed empirical data to clarify the characteristics of SC and how it leads to in- creased levels of HIV sexual risk behavior. Specifically, this study uses a case-control design to compare two groups of MSM, 125 MSM with SC and 125 MSM without SC. We will recruit participants from the community using Craig's list, a newspaper that targets the GLBT community, and posting flyers in neighborhoods with high concentrations of GLBT residents. We will also recruit from a treatment program that provides services for substance abuse and sexual compulsivity in GLBT individuals. Our study explores the relationship between sexual arousal and negative mood by measuring sexual arousal to erotic stimuli following the induction of two types of negative mood (depression and anxiety). We explore the influence of behavioral activation, sexual excitation, behavioral inhibition, and sexual inhibition by the use of four standardized psychometric measures, and we explore the influence of cognitive control through the use of three cognitive tasks: the Stroop task that measures conflict monitoring, the Reversal learning task that measures inhibitory control, and the Delayed dis- counting task that measures the tendency to favor either smaller immediate or larger delayed rewards. This multi-method strategy will allow us to characterize SC and to provide needed empirical data to identify, and therefore help address, the underlying mechanisms that influence unsafe sexual behavior. The findings of this study will further a nuanced approach to the development of interventions and allow for targeting the most re- source-intensive prevention efforts at those individuals most likely to spread HIV. N:\SPA Research\Grants\Miner RO1 resubmssion Jan_2011\Final Documents\Project Summary 12-30-2010.docx